The manufacturer's recommended operating voltage for electronic processing arrangements is often chosen to minimise errors. Typically, the lower the supply voltage, the higher the rate of errors in the output of the electronic processing arrangement. Recommended operating voltages are usually notably higher than the voltage at which errors would begin to occur. This is because manufacturers include a voltage margin in an effort to account for a number of possible variable factors, for example supply voltage error, silicon process parameters, temperature effects, radiation and transistor age effects.
Various voltage selection methods which aim to reduce the operating voltage without losing system accuracy are known. By operating a system at lower voltages, the overall power consumption of the system may be reduced. For example, it is known to vary the voltage based on clock speed. It is also known to use a device to calculate an appropriate processor voltage based on the operating conditions of a processor, the calculated processor voltage including a safety margin akin to that implemented by manufacturer nominal operating voltages, and to control a supply voltage to the processor accordingly. Furthermore, it is known to operate a processor cache at a fixed voltage value low enough to incur erroneous cache outputs, and then to attempt to correct those erroneous outputs. Additionally, processors designed to allow the voltage to individual components of the processor to be controlled internally are known.
In data processing systems provided on spacecrafts it is common to use primary and redundant processing elements to carry out processing tasks in parallel. The power consumption of the overall system is then the combined power consumption of the primary processing elements and the redundant processing elements.
The invention was made in this context.